Metástasis intramedular de un carcinoma mamario en un gato

espanolSe remite un gato Siames, hembra y esterilizada, de 9 anos de edad, por paresia de las extremidades posteriores y masas mamarias. El examen neurologico revelo una paresia ambulatoria de las extremidades posteriores, con perdida de propiocepcion y presencia de reflejos espinales, compatible con una lesion en el segmento medular T3-L3. Tras un estudio citologico con un resultado compatible con carcinoma mamario y signos radiologicos tipicos de metastasis pulmonares, se le practico la eutanasia. En la necropsia, se encontraron multiples nodulos subcutaneos, firmes, de 0,2 a 2 cm de diametro en glandula mamaria, region lumbar y esternal, espacios intercostales y musculo esqueletico de ambas extremidades posteriores. Histologicamente, la neoplasia mamaria se diagnostico como carcinoma tubulopapilar simple, con areas de comedocarcinoma. En la medula espinal (segmento L1-L2) se hallo un nodulo metastasico de gran tamano que expandia la sustancia blanca y comprimia la gris. Nodulos similares estaban presentes en pulmon y musculo esqueletico de los miembros posteriores, mostrando la mayoria de ellos un patron de comedocarcinoma. Segun la bibliografia consultada, esta es la primera descripcion de metastasis intramedular de carcinoma mamario en un gato; esta condicion deberia incluirse en la lista de diagnosticos diferenciales de paresia en gatos con tumores de mama. EnglishA nine-year-old neutered female Siamese cat was referred to the Veterinary Hospital for hind legs paresis and mammary masses. Complete neurological examination revealed weight-bearing paresis with proprioceptive deficits on both hind legs with spinal reflexes compatible with a T3-L3 lesion. After cytology suggestive of mammary carcinoma and radiological signs compatible with pulmonary metastasis, the cat was euthanized. On necropsy, multiple white, firm, subcutaneous nodules, ranging from 0.2 to 2 cm were observed in mammary glands, lumbar region, sternum, intercostal spaces and skeletal muscle from both hind legs. The main histological finding was a simple tubulopapillary carcinoma with areas of comedocarcinoma in the mammary gland. A large metastatic nodule was observed in the spinal cord (L1-L2 segment) expanding the white matter and compressing the grey matter and central canal. Similar metastatic nodules were present in lungs and skeletal muscles from hind legs, most of them showing a comedocarcinoma pattern. To the authors’ knowledge, this is the first report of intramedullary metastasis of mammary carcinoma in a cat and this condition should be considered in differential diagnosis in cats with paresis and masses in the mammary gland.